40V, 1A Schottky for low-Vf rectification
The STPS1L40A is a 40V, 1A Schottky barrier rectifier from STMicroelectronics, housed in the common DO-214AC (SMA) surface-mount package. Its forward voltage drop is specified at 500 mV maximum when conducting the full 1 A rated current. The 40 V reverse voltage rating and 1 A average forward current place it in the standard low-voltage, moderate-current Schottky class — suitable for secondary-side rectification in 5 V and 12 V rail power supplies, freewheeling diodes across inductive loads, and reverse-polarity protection circuits where the forward drop directly affects efficiency.
Forward drop and leakage trade-off
The 500 mV maximum forward voltage at 1 A is the headline efficiency number — every 100 mV saved across the diode cuts conduction loss by 100 mW at full load. The reverse leakage is 35 µA at the rated 40 V, which is typical for a 40 V Schottky junction; leakage rises with junction temperature, so the trade-off between lower Vf and higher leakage at elevated temperatures is the main design consideration.
Active production, ROHS3 compliant
The base product number is STPS1, shared with other 1 A Schottky variants at different voltage ratings (20 V, 30 V, 100 V). The STPS1L40A is the 40 V member of that family.